The fourth approach we investigate is a bit different in what it has access to. Rather than training something ahead of time, here the robot at test time receives ground truth human observations from the human it is trying to predict, and uses them to determine whether its predictor is operating accurately or not in that particular new setting. This is directly inspired by [1]}: if at test time the human takes actions that are too low of a probability under the predictor, we conclude that the predictor is not correctly handling the current situation.
